186 | Climatic conditions influence feed intake and body weight in Equus caballus

Giulia Sisia, Francesca. Aragona, Francesco Fazio, Giuseppe Piccione, Elisabetta Giudice, Francesca Arfuso, Alessandro Zumbo, Claudia Giannetto | Department of Veterinary Sciences, University of Messina, Italy.

Horses are herd animals; in nature, the predominant species-specific behavior is the search for food, which occurs throught grazing. Modern management techniques for this species influence the instinctive behavioral patterns of horses kept in a domestic environment [1]. Despite the effects of domestication, horse behavior remains largely unchanged, suggesting that modern management practices used in horse breeding may conflict with the species’innate behavior and lead to welfare problems [2]. The present study evaluated the effect of seasonal climatic conditions on feed intake, body weight, and rectal temperature in horses maintained under a hot Mediterranean climate. Eight Italian Saddle geldings (10-13 years old; mean body weight 427.8±54.6 kg) were individually housed in paddocks (800m²/horse) and provided ad libitum access to hay. Feed intake, body weight, and rectal temperature were recorded every 10 days during four 30-day periods representative of different seasons (January, April, July and October). Environmental conditions were monitored continuously, and temperature-humidity index (THI) was calculated using an adaptation of Thom’s formula. Total and daily average feed intake were calculated for each season. The application of two-way ANOVA for repeated measure revealed no differences in the values of body weight and rectal temperature among the different seasons and data points (P > 0.05). The application of one-way for repeated measure ANOVA on the total and daily average feeding ingestion showed no statistical difference among seasons (P > 0.05). A statistically significant positive correlation was found between feed intake and body weight (P < 0.05), indicating a coherent regulation between nutrient intake and body mass. All parameters showed low inter- and intra-individual variablity across season. Despite the higher THI values recorded during the summer period, all measured parameters remained remarkably stable, showing low inter-and intra-individual variability. These results suggest that horses kept in paddocks and feed ad libitum with homogeneous high-quality hay are able to maintain stable physiological and nutritional parameters throughout the year, even when exposed to hot Mediterranean summer conditions. The study demonstrates that horses housed in paddocks and fed ad libitum with homogeneous-quality hay maintain similar values of rectal temperature, body weight, and feed intake. This implies that horses kept in paddocks located in Mediterranean areas remain in a state of welfare according to the parameters herein investigated. The results gathered in the current study suggest that horses herein investigated have an affective physiological and nutritional adaptation to seasonal climatic variations, including summer heat cindition.